Cyclodextrins are cyclic oligosaccharides which consist of 6, 7 or 8 α(1-4)-linked anhydroglucose units. The α-, β- or γ-cyclodextrins, which are prepared, for example, by enzymatic starch conversion, differ in the diameter of their hydrophobic cavity and are generally suitable for the inclusion of a large number of lipophilic substances.
Acylglycerols comprising high amounts of ω-3 polyunsaturated fatty acids, for example eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosatetraenoic acid (DTA), or docosapentaenoic acid (DPA), are employed in the food and dietary supplement sector to provide essential fatty acids. Essential fatty acids have been linked to the overall health and wellbeing of humans and to the treatment and prevention of diseases associated with the cardiovascular system, inflammatory disorders, human development, fitness, and performance.
The limited stability of ω-3 polyunsaturated glycerol esters discourages their wider use. This instability results from enhanced sensitivity to oxidative decomposition (e.g. by exposure to light, atmospheric oxygen, heat or microorganisms) due to the large number of carbon carbon (C—C) double bonds. Autoxidation takes place at the C—C double bond, which leads primarily to the formation of peroxides, and then to aldehydes, ketones and acids. Secondary reactions involve isomerizations and polymerizations.
U.S. Pat. No. 5,189,149 discloses a method of producing complexes of long chain polyunsaturated fatty acids, their salts and esters inclusive of fish and vegetable oil glycerides, with α-, β- and γ-cyclodextrin (α-, β- and γ-CD) and hydroxypropyl-β-cyclodextrin, and the resulting complexes. This patent does not disclose the composition of their resulting complexes, or their stability.
U.S. Pat. Nos. 4,831,022; 4,777,162; and 4,775,749 disclose inclusion compounds of eicosapentaenoic acid and γ-cyclodextrin and food products containing the inclusion compound. These patents teach that the complex has the highest eicosapentaenoic acid content when γ-CD is used as cyclodextrin. The patents further disclose the high stability of the eicosapentaenoic acid/γ-cyclodextrin complex. The patents do not disclose complexes of derivatives of eicosapentaenoic acid or other ω-3 polyunsaturated fatty acids with γ-CD.